The present invention relates to an instrument for the treatment of interdental surfaces, which is plug attachable to on an a power driven dental apparatus, wherein the apparatus has an angle piece in which rotary motion is converted into reciprocating motion and the instrument is removably fixed in the head thereof. Such an apparatus is described in the German Pat. No. 1 766 651 and it is used with a set of instruments with rigid diamond tips having a triangular profile and a full holding part. Water which is required during the utilisation of diamond tips is directed from outside the angle piece against the tip. Diamond tips that are available on the market are coated only with a coarse type of diamond grain.
Another instrument is described in the U.S. Pat. No. 1 354 139 which, however, does not utilize diamond tips and wherein the body of the tip is reinforced and thus rigid.